Issue Description

After K2 Five RTM Fix Pack 21 is installed and you open a worklist item in K2 Workspace or using a rule in K2 Designer you will be presented with an error.

Error Message

The following error occurs: “Worklist item could not be opened. Unable to cast object of type ‘System.Byte[] to ‘System.String’.”


  1. Ensure you have K2 Five RTM installed.
  2. Get the K2 Five RTM FP22 from Regional Support.
  3. Install the K2 Five RTM FP22 to apply the fix.
  4. It is recommended to refresh the browser cache.